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Finding the Fourth Proportional to 129.16, 193.65 and 81.10

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Solution

The fourth proportional to 129.16, 193.65 and 81.10 is: 121.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    129.16 : 193.65 = 81.10 : x
  2. Step 2: Convert to fraction form
    129.16/193.65 = 81.10/x
  3. Step 3: Cross multiply
    129.16x = 193.65 × 81.10
  4. Step 4: Simplify right side
    129.16x = 15,705.02
  5. Step 5: Solve for x
    x = 15,705.02/129.16
  6. Step 6: Final answer
    x = 121.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.